Bug #931

[Dusan Vujosevic]

I seems that the problem I noted in bug #931 goes away when 
"PerfectGraphics" is set to false (????). I tracked the problem down to 
implementation of PATINVERT in BITBLT_InternalStretchBlt() (in 
graphics/x11drv/bitblt.c). It check whether 'perfect_graphics' is on and 
if it is it actually doesn't do the drawing:

     case PATINVERT:  /* 0x5a */
	if (perfect_graphics()) break;

Maybe I'm missing soemthing here but I think that test should be:

     case PATINVERT:  /* 0x5a */
	if (!perfect_graphics()) break;

That would give a more logical behaviour where there would not be any 
drawing errors when "PerfectGraphics" is set to True. (There are other 
spots where this is used in similar fashion)

Another question is why have the "PerfectGraphics" option at all when it 
  produces drawing artifacts?

D.